Glue



United States Patent 2,694,013 GLUE Worth C. Goss, Houghton, Wash., assignor to The Sheetwood Products Company, Seattle, Wash., a corporation of Washington No Drawing. Application December 18, 1951, Serial No. 262,330

3 Claims. (Cl. 106163) This invention relates to improvements in mixtures that are especially useful as glues or bonding agents in the making of sheet lumber from wood fibers, or the like; the present invention being a continuation in part of my copending applications, Serial No. 35,519, now Patent No. 2,578,695, issued December 18, 1951, and Serial $095,000, now Patent No. 2,581,652, issued January It is the principal object of the invention to provide an inexpensive glue containing the brown rotted wood glue of my U. S. Patent No. 2,485,587.

In explanation it should be understood, that in general, I prefer to make sheetwood boards from raw ground wood fiber, preferably of rather acid character such as that derived from western red cedar, California redwood or Douglas fir. I have found when these woods are used together with a certain percentage of parafline, such as 3% to 4% and in conjunction with my rotted wood glue that an almost perfectly water-proof and weather-resistant board is prepared which is strong, durable, highly workable for routing, sawing, planing or shaping. A properly prepared board using western red cedar fiber and 15% of my rotted wood glue mix will have a strength as high as 4000 lbs. modulus of rupture, and a density of .65. As an example of the invention, I prepare long silky fibers from western red cedar, add 4% of a crude parafiine wax. In the trade this material is called slack wax. To the damp fibers and parafiine mix I add 15% of a glue prepared from 10% brown rotted Wood and 5% urea, with sufiicient ammonia added to the glue to give a pH of 9.0. This brown rotted wood is ground with water to a very fine paste, and added thereto is 5% of the urea, or a similar amide product containing NHz group or NH group, plus ammonia.

Another suitable product to add to the rotted wood paste would be dicyanimide, commonly known as dicy. There are other reagents that contain the amide group, or NH groups, such as melamine or biuret which would be suitable for this purpose. The urea and the rotted wood glue work in conjunction with each other; the urea tending to soften and make the rotted wood glue flow. .Urea also protects the fibers of the board from deterioration during the application of sufficient heat to make the rotted wood glue set to a strong, hard, waterproof plastic.

2,694,013 Patented Nov. 9, 1954 I then thoroughly mix the cedar fiber, the parafline, the 10% of rotted Wood mix and the 5% of urea and ammonia into a fluffy, damp mix which may be sifted through a screen. This mix is sifted through a screen onto a waxed stainless-steel plate and enough material is added to the pad to make the thickness and density of board desired. To make a board /2" thick and a density of 7/10, 1.82 lbs. of this dry fiber rotted wood glue mix is added per square foot of the area of the board to be pressed. I usually use a form which confine's the fiber mix to the size of board to which I desire toFpress. "This form is withdrawn after the pad is com- ;pacted and a screen, preferably about 14 to 20 mesh, which is thoroughly waxed with paraffine, is laid on the back of the damp pad. This pad lies on the stainless steel sheet with the screen on the back thereof, is then put into a press, preferably of a temperature of 415 F. This press is capable of exerting a pressure of about 150 lbs. per square inch and the damp pad is pressed for a period of about seconds, at a pressure of about lbs. per square inch. This serves the purpose of glossing the surface, giving it a bright glaze, during which time the plastic flows and the board acquires a very attractive glaze. The pressure may then be reduced to a very low pressure such as 10 lbs. per square inch and the board held in the press until it is dry, and usually about 10 minutes beyond the time of drying. This serves to let the board reach the temperature of the press and to set chemically so that the rotted wood resin is waterproof, insoluble, and infusible. Made in this manner the board will have the following characteristics: At a density of between about .65 and .70 it will have 4000 lbs. modulus rupture. It will absorb not more than 10% of Water in twenty four hours soaking, and the product will have a fine commercial appearance, suitable for almost all types of carpentry work.

Having thus described my invention, what I claim as new therein and desire to secure by Letters Patent is:

1. A glue comprising a mixture of brown rotted wood, ammonia, and an amide selected from the group con sisting of urea, dicyanamide, melamine and biuret.

2. A glue comprising a mixture of brown rotted wood, an amide selected from the group consisting of urea, dicyanamide, melamine and biuret, and suificient ammonia to give the mixture a pH of 9.0.

3. A glue comprising a mixture of two parts brown rotted Wood ground to a wet paste like mixture, one part urea and sufficient ammonia to give the mixture a pH of 9.0.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,298,017 Loughborough Oct. 6, 1942 2,485,587 Goss Oct. 25, 1.949 2,581,652 Goss Jan. 8, 1952 

1. A GLUE COMPRISING A MIXTURE OF BROWN ROTTED WOOD, AMMONIA, AND AN AMIDE SELECTED FROM THE GROUP CONSISTING OF UREA, DICYANAMIDE, MELAMINE AND BIURET. 